I have a group of users that need to be able to add/edit documents to a library but not create their own view. What permission level should I give them?
Updating my answer as I misunderstood your question: you will need to create a custom permission level as described here. Permission Levels is on of the Permission tools under your site permissions. Create one and uncheck the Manage Personal Views" option.
Creating public views requires Design permissions, so Contribute permissions would prevent them from doing that. The default permissions are outlined here.